When to quit?

[1946Zephyr]

Re: When to quit?

No, the reeds are fine. 80 PSI on an old QD like this, is decent. The compression is dead even with the two. So count the reeds out for being the problem.

If the carb is nice and clean inside, I highly doubt if this is the problem too.

Back to the ignition system:

Did you replace the spark plug leads when you rebuilt the ignition system? A lot of people will replace the coils without replacing the spark plug leads. Even if they do, often times the connection from the coil to the spark plug lead is not very good. The faces of the coils also have to be lined up with the machined face perfectly or you're spark will not be perfect. Those who run the old spark plug leads after changing the coils will often overlook the spark plug boot connections too.

I still think your issue may be in the ignition system.

 

[bktheking]

Re: When to quit?

How do reeds have an effect on compression? I had a reed stuck open and had 100 psi on both cylinders, reeds are on the intake side, compression is made above the ports, that's why compression and reeds don't do together and almost always have to be visibly inspected to ensure they are good. The telltale is either the missing "woosh" suction sound twice on each flywheel revolution , a plug that is constantly gas soaked with good spark or puking gas out the carb, sometimes terrible idle, they almost always run even though a reed issue could be present. This is a "no start" condition IMO.


Unless i'm way off base ????

 

[jbjennings]

Re: When to quit?

From my small experience, stuck open reeds will keep the motor from being able to push fuel into the crankcase, thereby preventing it from starting. However, stuck open or closed reeds will have no effect on compression.
If it's bad reeds, the motor should still crank up momenarily if fuel/oil is sprayed directly into the spark plug holes. I personally think this motor is not getting sufficient spark, as that is almost always what keeps mine from cranking. These oldies WANT to run if they have the spark that they need.
Anyway, it shouldn't take 10 minutes to pull the intake manifold and check the reeds to see if a bug or whatever is blocking them open. But they're rarely the problem and the problem can be pointed to if it won't crank at all without fuel being sprayed directly into the cylinders via the plug holes.
JMO,
JBJ

 

[jbjennings]

Re: When to quit?

BTW,
Be very careful if you choose to pull the intake that you remove every screw! There are a couple of hard ones to spot inside the manifold that must be removed before it will come off. If you pry on the manifold with much force you are guaranteed to ruin it. I wouldn't pull it unless it will crank with fuel in the cylinders, but not without it.
JBJ

 

[JB]

Re: When to quit?

Please stop throwing parts and money at your outboard and do some systematic troubleshooting. Try this, try that isn't much better.

Look in the Top Secret File at the top of this forum.

Good luck, and when you know what system is not working come back and tell us about it.

 

[1946Zephyr]

Re: When to quit?

Well, interesting point about the reeds BK. As a matter of fact, I have a 10hp here that ran okay when I brought it home and happened to have found a reed leaf resting in by the bypass cover, when I removed it. So, even with a bad reed valve assembly, these motors can still run fine. LOL

I agree with jbjennings here. The motor may not be getting sufficient spark.
Also, like he says, these oldies are very co-operative, if everything is set right.

 

[FHB]

Re: When to quit?

Systematic approach? I am not much of a small engine mechanic, but here goes.



I have an electrical problem and/ or a fuel problem. Compression seems to have been excluded with 80 psi in each cylinder.

I bought a spark tester and will check in am.

Differential Diagnosis of spark problem includes:
-Connection of ignition wires to coils- seems like a terrible design
-Orientation of coils to lateral walls of magneto plate (as these are pre-drilled holes I see no practical way to line anything up differently short of drilling new holes or filing out pre-existing holes.
Plugs, points condensors are new. I will get someone else to independently check point gap.
All wires have been replaced with pricey copper core wire,

Fuel-
Some one mentioned packing on needle vallves- All I have in there are 2 black rubber o -rings.

Needle adjustment on Hi speed needle has been 1 turn out as per instructions on rebuild kit, though I have seen some advocate 3/4 turn. I smell gas on the plugs after pulling the cord a few times. The new plugs I put in sure foul up fast.



Need to consider a completely mucked up carb. This happened to me once with an old VW carb after getting bad gas full of sediment. I could never clear out the idle jets. When I got the motor, the carb was mega grungy.

I have been able to get the motor to run for a few seconds with a squirt of fuel/oil mix in the spark plug hole. I have at times had it running for a minute or two without doing this. More usual routine is a backfire or 3-4 firings after a pull. I do not know what that means. It seems like a lot of oil ends up in the water barrel- I am running 20:1.

I looked in the intake at the holes on the intake side where the reed valves are supposed to be. They seem all closed and do not open with pulling the cord. I am told these hardly ever go bad.


My plan is to check the spark with the spark tester. Do a sync next if spark is OK. I still think that is the problem. The spring that pulls back the cam that rubs on the magneto plate is missing and I need to replace it. If that does not work I am going to replace the carb.

If all that doesn't work I am going to bend a piece of fence post 90 degrees , weld it to the head and use the whole thing as an anchor.

Frank

 

[samo_ott]

Re: When to quit?

Whoah. Black rubber O ring packing nuts??? I think you used the wrong ones. They should be two thin cork like packing nuts on each needle. I dunno what you used. I would re investigate that.

Also, test the spark. Get the proper tester. Ensure a strong blue snap over 1/4" or 3/8" or so.

80# and 80# is fine. There's no problem there.

 

[JB]

Re: When to quit?

Please tell us the results you get when you do this: http://forums.iboats.com/showthread.php?t=158071

Good luck.

 

[FHB]

Re: When to quit?

There is no spart on the top cylinder and good spark on the lower using the spark tester. I may have more than one problem here, but I amg oing to pull off the flywheel and find out what is happening. I just regapped the point and have a new condensor and coil. Has anyone ever bought a brand new bad coil?

I think next step is a synchronization and if that fails will replace the carb. I had a VW carb once that got irretrievably ruined after a bad load of gas. I was never able to sucessfully rebuild it. This one was plain nasty when I got it.

 

[bktheking]

Re: When to quit?

Can happen but very rare, if the coil is new and everything else is good (wired correctly, coils installed correctly, points gapped, good ground, good condensors) the plug wire is bad, I'm starting to get into the habit of keeping 10 ft of copper core wire in my garage as it seems that every motor I touch that needs new coils and such has bad wires as well. While you are in there replace BOTH of them. If you replaced the wires then it might not be making good contact to the coil.

 

[FHB]

Re: When to quit?

I really do not care for the connection to the coli on this motor. You are just supposed to jam the wire in to that pin on the coil assembly. The magneto moves alot and it seems to me a forgone conclusion it will get itself disconected.

fhb

 

[bktheking]

Re: When to quit?

That could be your problem, the coil end where the plug wire goes in (if they are indeed new coils and not used) are screws, you need to screw the wires in clockwise into the coil until you can't screw them in anymore. Almost all the mag's i've worked on have some sort of retainer held on by a threaded screw to lock the wires in place at the bottom of the plate where the wires route, this prevents the wires from being pulled out of the coils. When I install new wires I spread the center of the core to make sure the wire screws into the center of the core and not off to one side. The new coils should also have boots which go over the end of the coil where the wire goes in.

 

[jonesg]

Re: When to quit?

I really do not care for the connection to the coli on this motor. You are just supposed to jam the wire in to that pin on the coil assembly.
fhb

No you aren't.
Thats why you don't have spark, the wire should be screwed onto the spike in the coil output. Thread it on ...regardless how you think its supposed to be installed. You might find the spike has broken off now.
Did that one myself.!

 

[DJ]

Re: When to quit?

Heed some specific advice from above:

1. Spray "pre mix" into the plug holes (NOT STARTING FLUID). Run???

2. Spray some pre mix into the carb throat? Run???

I tend to think you have ignition issues too. Just because you have spark does not mean it is good enough or at the right time.

 

[FHB]

Re: When to quit?

I have sprayed gas mix ito the cylinder and gotten a sputter or two but no sustained running.

I feel really stupid about the ignition wires and willl take the whole thing apart and screw them on.

Using spark tester I have good spark on one cylinder.

Small engines this old are simple and minmally engineered, but if you don't get it all right it wont run.

Frank

 

[Biged007]

Re: When to quit?

Welcome to the wonderful world of antique motor repair and yeah it can be a lot of fun and rewarding. I liked the advice of solid copper wires and once you get them screwed in right and tight wait for the manual I would pay close attn. to the timing section as i believe also that you might have an issue there. one last thing ask your parts guy if they have a plug(s) that are a bit hotter range the prob. with today's plugs are they are not designed for the amt. of oil used in these older engines.
to this day I still have my Scott Atwater from the age of thirteen or exactly 40 years ago (birthday present from dad in Sept. of 1970)

 

[Biged007]

Re: When to quit?

Well, interesting point about the reeds BK. As a matter of fact, I have a 10hp here that ran okay when I brought it home and happened to have found a reed leaf resting in by the bypass cover, when I removed it. So, even with a bad reed valve assembly, these motors can still run fine. LOL

I agree with jbjennings here. The motor may not be getting sufficient spark.
Also, like he says, these oldies are very co-operative, if everything is set right.

Love the signature Former Marine or Sea Bee ?

 

[Haffiman]

Re: When to quit?

................ I'm starting to get into the habit of keeping 10 ft of copper core wire in my garage as it seems that every motor I touch that needs new coils and such has bad wires as well. While you are in there replace BOTH of them. If you replaced the wires then it might not be making good contact to the coil.

Pure copper core is probably the worst to use in outboard sparkplug wires. Used in salt water, they turn to green dust before the sun goes down!
Buy a reel of the original OMC plug wires.

 

[Tim Frank]

Re: When to quit?

Pure copper core is probably the worst to use in outboard sparkplug wires. Used in salt water, they turn to green dust before the sun goes down!
Buy a reel of the original OMC plug wires.

Check his address.
Fresh water boater and copper core is the way to go....